Modern Vespa

Warning lights and sounds come on during acceleration. The engine stalls and doesn't go above 2000 RPM. The engine can be started. The tilt switches don't function. No response. The roll lock doesn't engage. It's currently free.

https://youtube.com/shorts/dmysEqLqQD8?si=Pk70gxR7kA2taXSi

Checked the fluid level for the roll lock system?

I checked it three days ago and it was above low. I think there's no problem if I add more. I'll check again.

During accelleration? Maybe the speedsensors in the front wheels or its connectors? If the rollock system detects a fault in those sensors it will also react.

The problem occurred during acceleration. Thank you for the helpful information. I will head to the site early this morning and replace the speed sensor. By the way, I just checked the battery at the site and it was generating 14V and had plenty of Roll Lock fluid.

Starting to sound like the seat sensor IMO.

Does one of the warning lights go out when you sit on it?

Agree, sounds as this is the problem (don't accelerate over 2K RPM and no disengage the tilt-lock)

Good morning. It's currently morning in Japan. I went to the site early this morning and replaced the speed sensor, but there was no change. That's unfortunate. I'll bring it back and try replacing the roll lock ECU. I look forward to hearing more information.

Not likely to be a bad ECU

I'll take it home today. I'll test it again and be sure to report the results. Thank you everyone for watching and for your advice. I'll do my best.

I removed the connector for the seat sensor and bypassed it with a 3 ohm resistor, but it didn't make a difference. I remember that if the seat sensor is broken or the connector is removed, the warning light comes on but the warning sound doesn't come on. Either way, I'll continue to investigate. Thank you everyone. https://www.instagram.com/modern_vespa_?igsh=YXZua3VtdDlyeWdt

Not 3 ohm! 3k ohm - i.e. 3,000 ohms.

3kΩの書き間違いです。スミマセン。結局家に持ち帰り、予備のロールロックecuを3個を使い検証しました。しかし症状は変わらずでした。何度かコネクターを抜いたり挿してるうちに直ってしまいました。搭載しているecuを含めて4個検証しましたが全て正常に稼働しています。接触不良を疑い接点復活剤を使いコネクター類は全て清掃しました。少し腑に落ちませんが直ったので様子をみてみます。
https://youtube.com/shorts/DWo6KugdvjI?si=MxIWIqJYevhRd3IO

What is the loose wire running next to the main wiring looms?

Perhaps it is just the picture, but that wire looks pinched or damaged in a couple of spots

The wiring you see on the side is a USB connector added by the previous owner. It was removed before the problem appeared. I slept on it overnight and thought about it, and it seems the radiator cap was loose, causing coolant to leak. It's unlikely, but I think the radiator fluid overflowed when accelerating and got onto the connector and wiring, causing the leak. I'll run it for about a week and report back.

https://youtube.com/shorts/DWo6KugdvjI?si=ZaZ-JtommmJ1oNDU

I unplugged and plugged the connector in several times and it was fixed. Poor contact?

I've said it before and I'll keep saying it "The Italians may have invented electricity but they mastered the art of electrical malfunction"

I've owned enough Italian vehicles of all types with electrical quirks to make me realize that the only two brands that know how to put a vehicle together are Toyota and Honda

I like the original Piaggio. Of course, Yamaha and Honda too. I don't think engineers design things with the expectation that they will break, so I won't be sarcastic. I appreciate the passion of all engineers.

Well, how shall I put this?

The Italians create things purely based on emotion and image while the Japanese create things based on logic and a focus on reliability and durability.

Of course my viewpoint is a bit biased since I work for Honda

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Before my disability retirement, I did engineering in factories on their automated equipment. I designed new systems, did troubleshooting on existing machines and upgraded many machines to make them more efficient and reliable. I eventually stopped being amazed at the quality of engineering that goes out the door in finished products! Too many engineers just don't ask what if. If you don't look ahead for potential failures and what will be caused by those failures then you create nightmares for end users and technicians. Then you add in the bean counters.....

It was completely fixed. The roll lock unit is MAT, the throttle body is original, the stator coil is from a 250, new ignition coil, new plug wires, new plugs, new speed sensor, new O2 sensor. My impression is that it's a physical problem, so it can be fixed by touching it. However, there are more sensors than a GTS, so the failure rate is higher. That's why it can't be repaired and is dismantled. There are plenty of parts on the market. My English is poor. Sorry.